The scope of the Institute's interdisciplinary effort will be expanded to encompass biophysical and physicochemical studies, as well as immunological approaches to the investigation of the effects of several environmental chemicals in vitro and in vivo, in various animal species. Biophysical analysis will deal with the interactions of polyanionic polymeric substances and cell membranes, also with the factors influencing the entry of such substances through the intestinal epithelium and subsequent phagocytosis of the macromolecules. Assessment of the immunological status of animals exposed to polychlorinated compounds, singly or in combination, will be associated with studies of the impact of immunosuppression on manifestations and mechanisms of toxic action exercised by chemical agents. Existing analytical chemical and biochemical programs dealing with pharmacokinetics of polychlorinated compounds and their hepatic effects will be expanded to include hepatic porphyrinogenesis, in relation to the interaction of hepatocytes and Kupffer cells. Histochemical and ultrastructural studies will emphasize the participation of lysosomes in these processes, as well as the capacity of these organelles to influence the consequences of exposure to a multiplicity of polychlorinated environmental contaminants. The impact on the adrenal will be a particular topic of biochemical and morphological study.